Today we have a chance to see the performance of well known AAC encoders like Nero, Apple and Coding Technologies (previous versions of Winamp). Also Fraunhofer have released their totally new AAC encoder.

There are 20 samples. Please, don't hurry. Take your time as there will be enough of it. It's better to do fewer samples per day and avoid a fatigue.The test will be open during 10 days (until July 27)

As always every single result is helpful. Have a good time testing it!

Ok, some listeners have started to send their results. It will be better if somebody who has already any results send them. It helps to prevent some simple errors related to ABC-HR application or any other at early stage. The listeners usually will get answer quickly if everything is fine.

Hello. I am trying to participate. I downloaded the sample pack above and used the decode all bat file. I can't get abc/hr to play anything yet.

Can someone point me to a tutorial? I see a training mode but I don't really know what I'm doing.

Edit Ok I checked out ff123 page. I have opened the config file for sample 1 after running decode all as well as decode sample 1 bat files. there are 6 wav files in the directory and they all play in winamp OK.

The main abc/hr page is blank with no samples selected or able to be played. I have tried to load the config file over and again with no result. Still can't play anything.

Edit 2 ABC/HR auto selected spdif out on my m-audiophile 24/96 rather than line. I can play and hear now. Still not sure what I am doing though

I can hear the samples now,yes. Finding fault with them is proving much harder in some cases. I can't even hear the lowpass which is really suprising me. Much more difficult than I anticipated. Not like listening to Blade at 96kbps

My first listening tests since many years I probably lost most of my skill, but it's very interesting for me to see if I'm still able to make a distinction between ~100 kbps encoding and an uncompressed PCM sound. I guess encoders have progressed during the last years. I remember that last time I tested LC-AAC at this bitrate, I was rather disappointed. But is was four or five years ago and I was at the apogee of my skill.

For now, I completed the five first samples. Well, it's interesting! It's nice to see that so many implementations in one test (but it makes the evaluation longer and harder).Thank you IgorC and other people involved for organizing it!

Question. I have used a short selection in the abx mode for a given sample. Once I use test mode,not training mode, I cant erase my results and try again in test mode. I can only use training mode even though I am checking a different time frame of the sample.

Question. I have used a short selection in the abx mode for a given sample. Once I use test mode,not training mode, I cant erase my results and try again in test mode. I can only use training mode even though I am checking a different time frame of the sample.

Is it supposed to be this way or can I reset back to test mode?

It is supposed to be that way and does exactly what it should. Don't start test mode until you have heard a complete sample and choose your "worst" section before starting the test mode.

Question. I have used a short selection in the abx mode for a given sample. Once I use test mode,not training mode, I cant erase my results and try again in test mode. I can only use training mode even though I am checking a different time frame of the sample.

Is it supposed to be this way or can I reset back to test mode?

It is supposed to be that way and does exactly what it should. Don't start test mode until you have heard a complete sample and choose your "worst" section before starting the test mode.

Thanks. I tested a few sections that I had been able to abx in practice mode and failed during the actual test. I was then able to pick another section that I was able to detect in practice mode but could not repeat the testing.

This is the first time I have used abx/hr. I will run more practice tests in the future before making a definitive test.

I'm going to try finishing this one; I never finished the first test I participated in here, and I didn't participate in the last one at all. (48kbps, which I might have actually had fun with).

One slight issue I've noticed so far: I was not able to identify the low anchor at all on Sample 3. Does this predict a problem for my results? The quality this test focuses is right on the edge of my transparent zone, so I don't want to risk tainting the results.

I'm going to try finishing this one; I never finished the first test I participated in here, and I didn't participate in the last one at all. (48kbps, which I might have actually had fun with).

One slight issue I've noticed so far: I was not able to identify the low anchor at all on Sample 3. Does this predict a problem for my results? The quality this test focuses is right on the edge of my transparent zone, so I don't want to risk tainting the results.

You'll get it. Its not mangled like the other samples but its there. Its definitely harder than the others.

If I remember the other listening test discussions, they reject results on certain criteria, like consistently incorrectly identifying the reference or giving it scores too low to be credible. Honest results should not taint but contribute to the experiment.

PS I think I'll get my son to join HA and give this a try. He is a music major and interested in music and music compression. Maybe he could get his friends interested....

As first observation, some listeners are expecting to hear the same artifacts as in past. And of course there are new versions of codecs and artifacts are different.The more listener tries to listen some particular artifacts the less chance to spot any of them. But if the listener just tries to enjoy the music itself then the artifacts appear themselves.

Also it's very important to mention about some practice with headphones. It's known that even good headphones can sound bad because of not optimal position on the head. It's easy to check. While the music is playing the listener should try different positions and distances (different adjustment of the rim) without set the headphones completely on the head. It might sound crazy but it works. More here:

It's so easy, but did you ever test for the optimal position of your headphone? With many headphones the soundstage and the balance of sound are strongly dependent on the position of the driver to our ears.

Scientific research has shown that our perception of depth is increased when the driver is placed more forward and lower with respect to the entrance of the ear channel.

Experimenting doesn't cost you anything and may improve sound considerably.

Have only had time to do two samples so far. (16 & 20) (I found this listening test just a few days ago.)

You can send a few results already now to be sure that everything is ok.

QUOTE

Igor, which samples should I focus on if I have to chose?

All of them.It's very unlikely to have enough results during first 10 days so it's more likely (almost sure) that test will be extended for another 10 days.

The rules are the same as from previous test with the small change of possibilities for ranking the references (3 instead of 4) because now there are less samples .

QUOTE

If the listener ranked the reference worse than 4.5 on a sample, the listener's results for that sample were discarded.If the listener ranked the low anchor at 5.0 on a sample, the listener's results for that sample were discarded.If the listener ranked the reference below 5.0 on more than 3 samples, all of that listener's results were discarded.

These rules aren't extremely strict in order to allow for simple humanerror while still excluding careless participants (*).

A stricter procedure to exclude all ranked references risks a systemicbias against any codec which are very good on a few samples and thussubject to more reference confusion by causing those samples to be excludedand weighing the test towards other samples.

(*)During the previous test some listeners have made the reasonable errors by accident (for example, have forgotten to rank the samples accidentally). But next time the listener wouldn't do such errors again.